Capacities MCP Plus

An enhanced MCP (Model Context Protocol) server for Capacities, providing seamless integration with your knowledge management system.

Note: This is a fork of jemgold/capacities-mcp with additional features and fixes.

What's Different from the Original

Feature	Original	Plus
Read Object Content	Not available	Retrieve full note content by object ID
fastmcp Version	1.27.3	3.25.4 (fixes MCP SDK compatibility)
Windows Support	May have issues	Tested with cmd wrapper
npm Package	capacities-mcp	capacities-mcp-plus

New Tool: capacities_read_object_content

Retrieve the full content of any Capacities object by its ID:

• Tries undocumented API endpoints first for direct retrieval
• Falls back to search API aggregation when direct access unavailable
• Provides title parameter to improve search accuracy

Features

This MCP server provides access to all current Capacities API endpoints:

• List Spaces - Get all your personal spaces
• Space Information - Retrieve detailed space structures and collections
• Search Content - Search across spaces with advanced filtering
• Read Object Content - Retrieve full note content by object ID
• Save Weblinks - Save URLs to your spaces with metadata
• Daily Notes - Add content to your daily notes

Installation

For Claude Desktop (macOS)

Add to your Claude Desktop configuration (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "capacities": {
      "command": "npx",
      "args": ["-y", "capacities-mcp-plus"],
      "env": {
        "CAPACITIES_API_KEY": "your_capacities_api_key_here"
      }
    }
  }
}

For Claude Desktop (Windows)

Windows requires a cmd wrapper. Add to %APPDATA%\Claude\claude_desktop_config.json:

{
  "mcpServers": {
    "capacities": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "capacities-mcp-plus"],
      "env": {
        "CAPACITIES_API_KEY": "your_capacities_api_key_here"
      }
    }
  }
}

Get your Capacities API key from your Capacities account settings.

That's it! The server will be automatically downloaded and run when Claude Desktop starts.

Development

Local Setup

For local development, you'll need to clone and build the project:

1. Clone this repository:

git clone https://github.com/Im-Hal-9K/capacities-mcp.git
cd capacities-mcp

2. Install dependencies:

npm install
# or
bun install

3. Copy the example environment file:

cp .env.example .env

4. Add your Capacities API key to .env:

CAPACITIES_API_KEY=your_api_key_here

5. Build the server:

npm run build

Running the Server

Start the development server with interactive mode:

bun run dev

For production use:

npm run start

To inspect the server tools and schema:

bun run inspect

Testing

Run the test suite:

bun run test

Code Quality

Check linting and types:

bun run lint

Format code:

bun run format

API Reference

Get your Capacities API key from your Capacities account settings.

For detailed API documentation, see:

• Capacities API Docs
• OpenAPI Schema

Available Tools

capacities_list_spaces

Get a list of all your personal spaces.

capacities_get_space_info

Get detailed information about a specific space, including structures and collections.

• spaceId: UUID of the space

capacities_search

Search for content across your spaces with optional filtering.

• searchTerm: Text to search for
• spaceIds: Array of space UUIDs to search in
• mode (optional): "fullText" or "title" search mode
• filterStructureIds (optional): Filter by specific structure types

capacities_read_object_content

Retrieve the full content of a Capacities object by its ID.

• objectId: UUID of the object to retrieve (can be obtained from 'Copy object reference' in Capacities)
• spaceId: UUID of the space containing the object
• title (optional): The title or partial title of the object - strongly recommended to improve search results
• How it works:
  1. First attempts to use undocumented GET endpoints for direct object retrieval
  2. Falls back to search API, aggregating content from highlights and snippets
  3. Filters search results by object ID to find exact match
• Note: When using search fallback, content may be incomplete as it's assembled from search snippets. Providing the title parameter significantly improves results.

capacities_save_weblink

Save a web link to a space with optional metadata.

• spaceId: UUID of the target space
• url: The URL to save
• titleOverwrite (optional): Custom title for the link
• descriptionOverwrite (optional): Description text
• tags (optional): Array of tags. Tags need to exactly match your tag names in Capacities, otherwise they will be created.
• mdText (optional): Text formatted as markdown that will be added to the notes section

capacities_save_to_daily_note

Add markdown content to today's daily note in a space.

• spaceId: UUID of the target space
• mdText: Markdown content to add
• origin (optional): Origin label for the content (only "commandPalette" is supported)
• noTimestamp (optional): If true, no timestamp will be added to the note

Rate Limits

The Capacities API has the following rate limits:

• /spaces: 5 requests per 60 seconds
• /space-info: 5 requests per 60 seconds
• /search: 120 requests per 60 seconds
• /save-weblink: 10 requests per 60 seconds
• /save-to-daily-note: 5 requests per 60 seconds

Example Prompts

Here are some example prompts you can use with Claude when this MCP server is configured:

Getting Started

"Show me all my Capacities spaces"
"What spaces do I have in Capacities?"

Exploring Your Knowledge Base

"Get detailed information about my main workspace in Capacities"
"What structures and collections are in my [space name] space?"

Searching Content

"Search for 'project management' across all my Capacities spaces"
"Find all notes mentioning 'machine learning' in my research space"
"Search for 'meeting notes' but only check titles, not full content"

Reading Content

"Read the content of object [object-id] from my research space"
"Get the full note content for [title] in my workspace"

Saving Information

"Save this article to my research space: https://example.com/article"
"Bookmark this GitHub repo in my coding space with tags 'javascript' and 'tools'"
"Save this link with a custom title and description to my resources space"

Daily Notes

"Add a summary of today's key insights to my daily note"
"Save these meeting notes to today's daily note in my work space"
"Add this quote to my daily note: [your quote here]"

Advanced Usage

"Search for 'productivity' in my work and personal spaces, but filter to only show task-related structures"
"Save this research paper to my academic space and add it to today's daily note as well"
"Find all my notes about 'AI tools' and then save the best ones as bookmarks"

Credits

• Original project by Jem Gold
• Enhanced by Im-Hal-9K

License

MIT - see LICENSE file for details.